[Starchy]

We have just come through a significant basement mold problem. In the completely finished basement, all of the exterior walls were torn out and the concrete and studs were treated for mold. Walltite polyurethane foam was sprayed on the concrete to avoid fiberglass insulation. New wallboard has just been installed and the yard has been re-graded to prevent water from coming in the windows, which was the root of the problem. Our house, a bungalow in west Quebec is 7 years old and is very tight. We heat the main floor with a wood stove and must keep a window cracked to keep it burning. The basement (2 bed rooms and my shop) is heated with electric baseboard heaters.
We are seriously considering an HRV by Venmar model 3100 with a HEPA filter. They have advised me that there is a limit to the footage of 8" flex duct than can be installed and this means that one basement bed room and our main floor office will not benefit from air circulation due to the layout of the vents for the HRV. Also, they advised me that if the house is kept at 22 oC (72 0F) and outside air is -20 oC ( 4 below zero F) that the recovered air will be 13 oC (55 oF). This will blow into one of the basement bedrooms and I think that is somewhat cool, especially for sleeping. Also, this air will be heated with electric baseboard and that costs money for this retired guy.
Questions: Are some HRV's more efficient at heat recovery than others? Is there such a thing as 240V fan assist baseboard heaters, to help move air around? Is an HRV essential?
Thanks for all replies.

[T-Top]

Why not use portable dehumidifiers in the basement. They are cheap and plus they create a heat load while running. To get rid of mold you need to remove the moister from the area.

[Starchy]

Thanks T-Top for your response. I have a dehumidifier running in the basement and I move it around from room to room. I have engaged an independent indoor air quality expert who made a number of recommendations. Firstly all 2x4's that come in contact with concrete (walls or floor) should have a vapour barrier between them and the concrete. ALL cracks in basement floor and walls must be repaired to reduce moisture transmission. Use of Dri-cor or like material on all basement floors is a very good idea. As well, a layer of 6 mil ploy under the Dri-cor is a good idea. And lastly, use an HRV that has a HEPA filter. If not used a lot to bring outside air into the house, it can still be used on recirc to filter airborne dust and allergens. Obviously it should be used to bring fresh air in, but it can get very cold here in the winter, like 40 below zero F. and on those days, recirc is fine. He said that it should not be piped with the flex tubing that they want you to use, but 6" ducting to improve air flow, or into your furnace ducts if you have one, I don't. Also, do not use the 2 in 1 pipe to the outdoors that they supply, in fact use 2 separate pipes, one for exhaust air and another at least 6 feet away for air intake. One last thought, he suggested strongly that we purchase a new wood stove that has the ability to be piped to draw outside air into the combustion chamber to eliminate the need to have a window open all winter to feed the current wood stove. We heat primarily with wood as I have lots and its free. So now, I will purchase an HRV, probably the Venmar 3100 as it has a HEPA filter built in and will install it over the winter. Will look for a new wood stove to install next spring.